If your device gets wet, it’s important to turn it off as soon as possible. After that, you have to remove the protective case so the remaining liquid won't go inside.
It’s important to keep your smartphone still and steady and not move as much as possible, the shaking increases the risk of water getting into internal parts.
Take a dry cloth and dab the water off from the phone’s surface. Let all the moisture dry up from the device before you start it.
In order to inhibit the liquid destroying everything, it is advisable to remove the microSD card asap.